The present invention pertains generally to the field of portable assemblies such as highway safety signs and light assemblies commonly fitted with pivoting legs to facilitate handing and storage, and more particularly to an adjustable leg system able to accommodate uneven terrain.
Several portable assemblies with pivoting legs have been developed in the art. U.S. Pat. No. 4,954,008 to Dicke discloses a quick release mechanism for locking a tubular leg member of, for example, a mounting base for outdoor signs and barriers. The quick release mechanism includes a lever arm, a pin and a resilient member. The lever arm is pivotally attached to the tubular leg. The pin passes through and extends beyond both sides of the tubular leg and loosely rides within a slot at the operating end of the lever arm. The resilient member fits beneath the handle end of the lever arm being in tensional contact with the outer surface of the leg and the bottom surface of the lever arm. To lock the leg in any position, such as in either the horizontal support position or in the upright compact position, the pin is pushed inwardly to an engaged position in the leg flange by the operating end of the lever arm. The pin is unlocked by pressing on the handle end of the lever arm which pulls the pin out of the engaged position in the leg flange.
U.S. Pat. No. 5,340,068 to Sarkisian discloses a release mechanism for a locking, pivotable leg for an assembly. The release mechanism includes a release pin having an enlarged head and transmission means to transmit movement of the release pin to the locking element moving it from its operative locking position. The transmission means includes a release pin spring shoulder, a locking pin spring groove and a pin slot in the leaf spring disposed to engage these two components. Movement of the release pin causes the release pin spring shoulder to deflect the leaf spring, which deflection is transmitted into movement of the locking pin in turn disengaging the locking pin from the locking pin hole in the base bracket, allowing the leg to pivot freely.
U.S. Pat. No. 5,611,509 to Kulp discloses a quick release mechanism for securing a member to a structure, such as a support leg to a sign stand. The member includes a slot having a bottom surface and the structure has a slot having an open top end. A latch member releasably attaches the member to the structure, and is adapted to extend axially through both the member and structure slots, so that a proximal portion of the latch member extends forwardly of the member slot and a distal portion of the latch member extends rearward into the structure slot. When the latch member proximal portion is actuated downwardly, its distal portion swings upwardly through the open top end of the structure slot, thereby disengaging from the structure slot and releasing the member so that it may pivot relative to the structure.
These systems, when deployed, must be inverted to release the legs for folding and storage. Due to the importance of worker safety, there is a need for a simple and reliable release system that works easily and quickly.
It is therefore an object of the present invention to provide a release system for locking and unlocking the foldable tubular leg members of a portable structure. The release system of the present invention can be operated by users without diverting their attention from their surroundings.
A further object of the invention is to provide a dual release system. For deployment, a lock pin can be retracted by the stepping action of a user's foot or pulled by hand. The same pin can be retracted for retrieval by a kicking action of a worker's foot or pulled by hand.
A further object is to provide a a dual release system that can be reliably operated by a highway worker without diverting attention away from the highway traffic adjacent to the work zone.
A further object is to provide a dual release system that is appropriate for all portable traffic signs and highway lights. These and other objects of the present invention will become better understood with reference to the appended Summary, Description, and Claims.